I just ran across this project called Server Sky. The idea is to build a server farm (i.e. lots of computers for web hosting and computing stuff) in space, where power is plentiful. The whole thing consists of paper-thin servers the size of a cube sat. I haven't read much of it yet, and don't have the time to do so now, but I figured I'd post it here, and then we can all figure out whether it's any good .

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus

I just ran across this project called Server Sky. The idea is to build a server farm (i.e. lots of computers for web hosting and computing stuff) in space, where power is plentiful. The whole thing consists of paper-thin servers the size of a cube sat. I haven't read much of it yet, and don't have the time to do so now, but I figured I'd post it here, and then we can all figure out whether it's any good .

Interesting idea. Lots of problems to be overcome.

Space isn't cold, at least the parts that have abundant solar energy aren't. The computing chips could probably be kept in the shaded region behind the solar panels, but the whole structure will have to have enough radiators to get rid of the heat captured via solar radiation. I haven't read anything about radiating heat from the serversats on the website, apart from an assumption that they will radiate enough heat by themselves. My guess is that they will quickly reach a temperature of about 450-550K which doesn't make for a good computing environment. This estimate may be inaccurate, but I'm pretty certain that additional cooling will be required.

"We can lick gravity, but the paperwork is overwhelming" -- Werner Von Braun"It's all fun and games until the potato chips get loose." (said of the ISS by Gizmodo on space.com)"A journey of a thousand miles begins with a single step. A journey of a hundred thousand miles begins with lots of flames, noise and smoke!" -- Emory Stagmer

just keeping on top of the environment induced bit errors would be problematic enough as it is,Cooling the systems would be the least of the problems...lol.

Yeah, let me just start with radiation, heat, cooling, power, bandwidth, ground support maintenance, software updates/enhancements/bugfixes, and then add on parts availability! Anybody who thinks this is workable has no idea what they're talking about. A 100Mhz PowerPC that will run in space is $500,000 and only has 36MB SRAM, 2MB EEPROM, no mass storage, and IS THE FASTEST RAD-HARD PROCESSOR THAT EXISTS. 100MHz. That's about 30x slower than most desktops today and costs 1000x as much!

"We can lick gravity, but the paperwork is overwhelming" -- Werner Von Braun"It's all fun and games until the potato chips get loose." (said of the ISS by Gizmodo on space.com)"A journey of a thousand miles begins with a single step. A journey of a hundred thousand miles begins with lots of flames, noise and smoke!" -- Emory Stagmer

I'm far from a space expert, and I don't know much about the level of radiation and how much is needed to fry a processor, but I think that the scenario here is somewhat different from current space applications.

First, 100MHz is about the lowest performance level hosted virtual machine that you can rent these days. Web and grid/cloud technology generally scales very well, so that a low performance-per-machine can be compensated for by just having more machines. Also I would probably use something ARM or MIPS-based rather than PowerPC, at least for web serving. Number crunching is something else again.

Second, if you have lots of machines, their individual reliability is not that important. A decent sized cluster has a broken hard disk every week, even here on Earth, just because the technology isn't perfect. Yet that doesn't make it unusable, far from. You just have one node less (or use RAID) until someone replaces the thing, which isn't that big an issue if you have hundreds or thousands of nodes. And at the Google scale of computation, you're not even going to bother replacing individual parts or even individual machines, you just use the entire data centre (which for Google is a shipping container packed full of computers, power supplies and cooling) until too many nodes break, at which point it's probably also obsolete, and then replace the entire data centre.

Now, as I said, I don't know much about radiation effects on CPUs in space, so I'm not sure that it's not just going to be blown to smithereens in seconds anyway, but this is not the same scenario as a satellite that has one CPU, with maybe one spare, and has to keep running for many years.

Third, if I understand correctly, the CPU radiation hardening process goes something like designing a special layout and creating a mask for it, and then using obsolescent machinery to make it, much larger than you would ordinarily do. Making masks is very expensive, and I imagine the cost will go up still if you have additional requirements beyond just that it will work. And then the market for space-rated CPUs is probably not much bigger than IBM's original estimate of the world market for computers. If they had really never sold more than five computers, then I but they would have cost much more than half a million dollars apiece. Chip manufacture is characterised by extremely high initial costs (not just the masks, also designing the chip itself), and comparatively low per-unit costs. So, volume counts, and these guys do seem to intend to buy a lot of them. The cost may not necessarily be an issue.

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus

The redundancy you're looking for would waste a huge amount of good hardware, that on earth could be in production as you'd be able to swap out the faulty bits and pieces.

Take an example, you'd want Raid 6 for your nodes - that means 2 nodes can fail without you losing any data.Then you might want to mirror those nodes with a second set of Raid 6 nodes with Raid 1. The amount of storage you then have is ("number of nodes" / 2) - 2 * storage capacity. Great - you have one of the better solutions for redundancy on the market, but how long would that last in space? And the price of the thing would be enormous. In addition you'd need a blindly fast network connection, and the computing power needed to calculate the Raid algorithms with that amount of data and that many nodes would be huge.

If you want cheap, environmentally friendly server farms, Norway is at your service, with reasonably priced electricity from hydroelectric dams, and abandoned mines with cold climate which doesn't require much cooling etc.